TOLUCA, Mexico — President Barack Obama sought to reassure leaders of Mexico and Canada of his commitment to new trade agreements between Asia, the Pacific and the Americas, even as he faces political resistance in the U.S. from members of his own Democratic party.

Obama arrived Wednesday in the industrial center of Toluca, about 40 miles west of Mexico City, for the start of a one-day North American Leaders Summit. Flanked by his trade negotiator and top Cabinet secretaries, Obama stepped off Air Force One and onto a red carpet to be welcomed by an honor guard. Cloudless skies and warm breezes set a sunny mood as Obama walked to his limo to be shuttled to an ornate government complex nearby.

Obama opened his trip with a bilateral meeting with Mexican President Enrique Pena Nieto, a discussion the U.S. leader said would focus in part on how to advance the Trans-Pacific Partnership, a trade bloc of 12 countries in the Americas, Asia and the Pacific.

The one-day meeting is being overshadowed by the violence that erupted half a world away in Ukraine as the government of President Viktor Yanukovych cracks down on protesters in Kiev. During brief remarks at the start of his meeting with Pena Nieto, Obama said the United States condemned the violence in Ukraine “in the strongest terms.”

Officials said the U.S. was weighing its options against those responsible for the violence, including consulting with the European Union on the use of sanctions. It’s not the first of Obama’s foreign travel to be eclipsed by unrelated events.

The summit occurs on the 20th year of the North American Free Trade Agreement among the three countries, a deal that has vastly expanded cross-border commerce in the region but that remains a contentious issue in the United States over its impact on jobs and on environmental protections.

Trade experts say the agreement is due for an upgrade to take into account the current globalized environment and to address issues not touched in the original pact. But rather than reopen NAFTA, the three countries are instead relying on negotiations underway to complete the TPP pact.

The Obama administration is hoping those negotiations are completed this year. The U.S. is also in the midst of negotiations over a Trans-Atlantic Trade and Investment Partnership with the European Union. But the president is facing stiff election-year resistance from Democratic leaders over his desire to get “fast track” trade authority, which would require Congress to give yes-or-no votes on the trade agreements without the opportunity to amend them.

“He is pursuing an agreement — TPP — that explicitly protects American workers and the environment and that he believes would be highly beneficial to our economy and the middle class,” White House spokesman Jay Carney said. “That’s the conversation he has and others have with lawmakers of both parties.”

Obama is sure to get quizzed by Pena Nieto on his prognosis for overhauling U.S. immigration laws, an issue of intense attention by Mexicans both in Mexico and in the United States.